1. Field of the Invention
The present invention relates to a laminated ceramic electronic component, and more particularly, relates to an improvement for reducing the layer thickness of an internal electrode in a laminated ceramic electronic component.
2. Description of the Related Art
For reduction of laminated ceramic electronic components in size, i.e., in thickness, it is effective to try to reduce the layer thickness of not only ceramic layers but also internal electrodes. For reduction of the internal electrode layer thickness, it is desirable that the thickness of the internal electrode be reduced to, for example, 0.5 μm or less.
However, when the internal electrodes have been reduced in layer thickness, the calcination for sintering raw laminates makes the electrodes more likely to be broken, thereby making the dielectric coverage of the internal electrodes to be decreased easily. In order to prevent this electrode breakage, it is necessary to sinter the ceramic constituting the ceramic layers at lower temperatures during calcination.
While it is common to add SiO2 as a sintering aid to the ceramic for the purpose of sintering at lower temperatures, a Li compound or the like may be added in the case of desiring sintering at further lower temperatures.
For example, in Japanese Patent Application Laid-Open No. 8-31232 (Patent Document 1), a rare earth element, Mn, Mg, Li, and Si are added to a BaTiO3 based dielectric ceramic. However, when the resulting dielectric ceramic is used as a material for dielectric ceramic layers in a laminated ceramic capacitor, a problem of structural defects are likely to be encountered. This problem is believed to arise from expansion due to oxidation of the internal electrode.